JPH065671B2 - Immersion type substrate processing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an immersion type substrate processing apparatus used for surface-treating a thin substrate such as a semiconductor substrate or a glass substrate for liquid crystal, and particularly to substrate processing. The present invention relates to an immersion type substrate processing apparatus, which is improved in terms of eliminating processing liquid vapor generated from a bath.

<< Prior Art >> As an immersion type substrate processing apparatus, for example, one shown in FIG. 6 (hereinafter referred to as Conventional Example 1) or one shown in FIG. 7 (hereinafter referred to as Conventional Example 2) is known. (Published July 30, 1987, "High Performance Process Technology II" edited by Semiconductor Technology Research Group).

In the conventional example 1, a plurality of substrate processing baths 102 are arranged, and a clean air flow down means 110 provided above the substrate processing baths 102.
And the inside of the clean air circulation space 108 formed below the clean air flow means 110 along the alignment of the substrate processing bath 102.
The substrate transfer robot 120 is provided so as to be movable (in the direction perpendicular to the paper surface of FIG. 6), and the forced exhaust ports 128 are arranged in multiples in the vicinity of each substrate processing tank 102. Clean air toward clean air distribution space 108
(Hereinafter, referred to as clean air) is flowed down to form the downflow F, and the processing liquid vapor generated from the substrate processing bath 102 is placed on the downflow F and exhausted from the forced exhaust port 128. In FIG. 6, reference numeral 125 is a substrate storage cassette that stores a large number of substrates W, and 114 is a front cover that partitions the clean air circulation space 108 from the external space.

On the other hand, in Conventional Example 2, in order to save the consumption of clean air more than the above, the clean air flow lowering means 110 with a small air supply amount
In addition to the above, a clean air outlet 130 is added to the front of the substrate processing tank 102, and a forced exhaust port 128b is added to the rear of the substrate processing tank 102, and air curtains A and C are formed on the upper side of the substrate processing tank 102 to remove processing liquid vapor. In addition to blocking the rise, most of the processing liquid vapor is placed on the air curtains A and C and exhausted.

<< Problems to be Solved by the Invention >> Among the above, in Conventional Example 1, in the clean air circulation space 108, in the vicinity of the substrate transfer robot 120, the down flow F hits the substrate transfer robot 120 and a turbulent flow occurs. However, there is a drawback that the processing liquid vapor adheres to the driving side portion 121 of the substrate transfer robot 120.

On the other hand, in Conventional Example 2, although the air curtains A and C are formed to solve some of the above problems, the substrate transfer robot 120 still allows the substrates to be sequentially transferred into the next processing tank. When the substrate accommodating cassette 125 is lifted above the air curtains A and C, a large amount of the processing liquid vapor rises as the substrate accommodating cassette 125 is lifted. If the processing solution vapor that has risen in this way adheres to the drive-side portion 121 and the like of the substrate transfer robot 120, it may cause a failure due to the erosion of the conductive contact portion. Therefore, in both of the above conventional examples, the clean air flow means 1
It is necessary to strengthen the downflow F by 10 to a certain extent, and the running cost is high.

If the downflow F is too strong, the inside of the clean air circulation space 8 has a positive pressure with respect to the external space such as a clean room, and the processing liquid vapor leaks out from the gap of the front cover 114.

On the contrary, if the inside pressure of the clean air circulation space 8 becomes negative, the particles intrude from the external space, and the significance of forming the downflow having an extremely high cleanness by the clean air flow lowering means 110 is lost. . Therefore, not only the balance between the supply and exhaust amounts, but also the airtightness is required.

The present invention has been made in view of such circumstances,
The first purpose is to prevent the processing solution vapor from leaking out or particles from entering from the outside, without considering the balance of supply / exhaust flow rate and airtightness, and the second purpose is to prevent the processing solution vapor from entering the substrate. The third purpose is to prevent the transfer robot from adhering to the drive side portion, and to reduce the running cost as a whole.

<< Means for Solving the Problem >> The present invention has been made in order to achieve the above object, and is an improvement of the device of the prior art 1 as follows.

That is, the clean air circulation space is partitioned into a high pressure chamber that has a positive pressure with respect to the external space of the immersion type substrate processing apparatus and a low pressure chamber that has a low pressure with respect to the high pressure chamber. Cover it with a high pressure chamber on the outside and face the low pressure chamber forced exhaust port,
The drive unit of the substrate transfer robot is arranged in the high pressure chamber, and the substrate support unit of the substrate transfer robot is arranged in the low pressure chamber.

<< Operation >> The operation of the present invention will be described with reference to FIGS.

According to the present invention, the substrate processing tanks 2, 2, ... Are covered with the low pressure chamber 8b and the high pressure chamber 8a from the inside with respect to the external space, and the processing liquid vapor is exhausted from the forced exhaust port 28. It does not leak to the high pressure chamber 8a side.

On the other hand, the low-pressure chamber 8b is covered with the high-pressure chamber 8a with respect to the external space, and the high-pressure chamber 8a prevents particles from entering the interior from the external space.

Further, in the substrate transfer robot 20, the drive unit 21 thereof has a high pressure chamber.
Since the substrate support portion 22 is disposed in the low pressure chamber 8b in 8a, a large amount of the processing liquid vapor is introduced from the high pressure chamber 8a when the substrate W is carried out to the outside of the substrate processing tanks 2, 2 ... The clean air is discharged from the forced exhaust port 28. As a result, there is no possibility that the processing liquid vapor will adhere to the drive unit 21 of the robot 20.

That is, the high-pressure chamber 8a has two functions of preventing leakage of the processing liquid vapor and preventing particles from entering from the outside.

<< Embodiment >> FIG. 1 is a schematic longitudinal sectional view of an essential part of an immersion type substrate processing apparatus showing a first embodiment of the present invention, and FIG. 2 is a perspective view showing an essential part of the apparatus in a broken manner.

In these drawings, reference numeral 1 denotes the whole of the immersion type substrate processing apparatus (hereinafter simply referred to as a substrate processing apparatus), and the substrate processing apparatus 1 has a plurality of substrate processing tanks 2, 2, ... The clean air flow means 10 provided above the substrate processing tank 2 and the clean air flow space 8 formed under the clean air flow means 10 are connected to the substrate processing tanks 2 and 2.
The substrate transfer robot 20 that moves to the left and right along with, and the forced exhaust ports 2 arranged in multiples in the vicinity of the substrate processing tanks 2.2.
8, the clean air circulation space 8 is divided into a high pressure chamber 8a and a low pressure chamber 8b, and clean air is introduced from the high pressure chamber 8a to the low pressure chamber 8b to remove the processing liquid vapor generated from the substrate processing tank 2. The forced exhaust port 28 is configured to exhaust air. The low-pressure chamber 8b may have a pressure higher than atmospheric pressure, a low pressure, or the same atmospheric pressure as long as it has a pressure lower than at least the high-pressure chamber 8a.

Each of the substrate processing tanks 2 is arranged in a drainage tank 5, 5, ... Which are partitioned and connected in series, and a liquid supply pipe 3 is connected to the bottom wall of each of the substrate processing tanks 2, 2. The processing liquid 4 is supplied through the liquid supply pipe 3 to cause the processing liquid 4 to overflow, and the processing liquid 4 discharged from the drain 6 of the drainage tank 5 is purified and circulated.

The clean air flow lowering means 10 has a blower fan (not shown) built therein, and comprises an air supply part 11 arranged at the top and an ultracleaning air filter 12 arranged below the air supply part 11. ,
The clean air is made to flow down toward the clean air circulation space 8 to form the downflow F. By the way, as the ultracleaning air filter, it is desirable to use a filter that can collect airborne particles having a particle diameter of 0.1 μm in the air with a high efficiency of 99% or more.

The clean air circulation space 8 is surrounded by the rear side wall 1b of the substrate processing apparatus 1, the laminar flow guide plate 14 hung down to the front side, and the air filter 12 so as to cover the substrate processing bath 2. There is. That is, the clean air circulation space 8 is substantially horizontal from the front partition wall 15 standing upright from the front side wall 5a of the drainage tank 5 and the intermediate height position of the upper wall of the front partition wall 15 to the rear side wall 1b. It is partitioned into a high-pressure chamber 8d and a low-pressure chamber 8b by the upper partition wall 16 provided in, and the drainage tank 5 including the substrate processing tank 2 is pressured from the inside to the external space (hereinafter referred to as a clean room) 40. The chamber 8b and the high pressure chamber 8a are covered, and the low pressure chamber 8b is arranged so that the forced exhaust port 28 faces it.

The front partition 15 is provided with an arm moving groove 15a and an arm elevating groove 15b for transferring a substrate by the robot 20, and the driving unit 21 of the robot 20 is placed in the high pressure chamber 8a while the substrate is being moved. The support portion 22 is configured to be able to convey the substrate accommodating cassette 25 in a state of being positioned inside the low pressure chamber 8b.

The upper partition 16 is made of a breathable mesh plate, punch plate, sponge material, or the like.
By restricting the flow of the downflow F together with the front partition wall 15, the internal pressure of the high pressure chamber 8a becomes a positive pressure with respect to the clean room 40, and the internal pressure of the low pressure chamber 8b is reduced by the forced exhaust port 28. Therefore, the high pressure chamber 8a acts so as to have a low pressure.

The laminar flow guide plate 14 has a downflow F at the front part inside the high pressure chamber 8a.
Is strongly flowed down to be discharged from the discharge port 26 on the lower side thereof, and a part of the downflow is caused to flow into the low pressure chamber 8b from the arm moving groove 15a and the arm elevating groove 15b. As a result, there is no risk that the processing liquid vapor generated from the substrate processing tank 2 will flow out to the high pressure chamber 8a side, and there will be no risk that particles will flow into the high pressure chamber 8a from the clean room 40.

Therefore, the drive unit 21 of the substrate transfer robot 20 is not eroded by the processing liquid vapor.

The laminar flow guide plate is preferably made of a conductive flexible synthetic resin material and its conductive portion is grounded in order to prevent static electricity from being charged by the downflow F.

FIG. 3 is a vertical sectional view showing a second embodiment of the substrate processing apparatus according to the present invention.

In this embodiment, the clean air flow space 8 is divided into the high pressure chamber 8a and the low pressure chamber 8b only by the front partition wall 30, and the clean air flowing down from the clean air flow lowering means 10 is larger in the high pressure chamber 8a, and the low pressure chamber 8a. 8b is different from the first embodiment in that the flow rate is controlled so as to decrease to 8b.

FIG. 4 is a vertical sectional view showing a third embodiment of the substrate processing apparatus according to the present invention.

In this embodiment, a substrate transfer robot is provided in the rear part, and accordingly, a rear partition wall 3 similar to the front partition wall 15 of the first embodiment.
2 is additionally provided, and the forced exhaust port 28 is made to face the rear side wall 5b of the drainage tank 5 to divert the exhaust flow downward, which is a difference from the first embodiment.

In the first to third embodiments described above, the substrate transfer robot 20 exemplifies the one in which the substrate storage cassette 25 is sandwiched and transferred by the substrate support portion 22, but the present invention is not limited to this, and as shown in FIG. 5, for example. Alternatively, the plurality of substrates W may be directly sandwiched between the pair of substrate support portions 22b without interposing a cassette.

<< Effects of the Invention >> As is apparent from the above description, the present invention has the following effects.

(B) The substrate processing tank is covered by the low-pressure chamber and the high-pressure chamber outside the high-pressure chamber, and the high-pressure chamber has the function of preventing the leakage of the processing liquid vapor and the particle invasion from the outside. The amount of balance and airtightness do not need to be so careful, and the cleanliness inside can be kept high.

(B) The drive unit of the substrate transfer robot is placed in the high pressure chamber to prevent erosion due to adhesion of the processing liquid vapor.
Failure of the robot can be prevented.

(C) The required cleanliness can be maintained simply by maintaining the internal pressure ratio between the high-pressure chamber and the low-pressure chamber within the required range.Therefore, a large amount of clean air is not required, and a blower for blower or exhaust The blower can be made smaller. This can reduce the running cost as a whole.

[Brief description of drawings]

1 to 5 show an embodiment according to the present invention, FIG. 1 is a schematic vertical sectional view of an essential part of an immersion type substrate processing apparatus according to the first embodiment, and FIG. 2 shows a required part of the substrate processing apparatus. FIG. 3 is a perspective view cut away, FIGS. 3 and 4 are equivalent to FIG. 1 according to the second embodiment and the third embodiment, and FIG. 5 is a front view showing another embodiment of the substrate transfer robot. is there. 6 and 7 are equivalent to FIG. 1 showing a substrate processing apparatus according to a conventional example. 2 ... Substrate processing tank, 8 ... Clean air distribution space, 8a ... High pressure chamber, 8b ... Low pressure chamber, 10 ... Clean air flow lowering means, 20 ... Substrate transfer robot, 21 ... Robot drive unit, 22 ... Robot substrate support unit , 28 ... Forced exhaust port.

Claims (1)

[Claims] 1. A plurality of substrate processing tanks, a clean airflow means provided above the substrate processing tanks, and a clean air flow space formed below the clean airflow means are connected to the substrate processing tanks. It is equipped with a substrate transfer robot that is movably provided alongside it, and multiple forced exhaust ports arranged near each substrate processing tank. Clean air flows down to the clean air distribution space by the clean air flow down means. To form a downflow, and the processing liquid vapor generated from the substrate processing tank is placed on the downflow and exhausted from the forced exhaust port. It is divided into a high-pressure chamber that has a positive pressure with respect to the external space of the device and a low-pressure chamber that has a low pressure with respect to the high-pressure chamber. Exposing the exhaust port to the substrate transfer robot Immersion type substrate processing apparatus characterized in that the driving unit is arranged in the high pressure chamber and the substrate supporting unit of the substrate transfer robot is arranged in the low pressure chamber.